cts pots are all over the place

[UCSDBoy]

Hi guys. I'm putting new cts pots into an RG I have - 2HB, 1 volume, 1 tone. I have about half a dozen pots on hand - all of them CTS. Putting them up to an ohm-meter, I'm seeing readings from 480k to 516k, when rotated to full open position. Do you guys think it makes much of a difference which ones I use?

 

[dave74]

Re: cts pots are all over the place

That's within normal specs,,,,,,,,,,I doubt you'd notice any difference but I'd always use the higher value if given the choice.

 

[hamerfan]

Re: cts pots are all over the place

That's within normal specs,,,,,,,,,,I doubt you'd notice any difference but I'd always use the higher value if given the choice.

This is not always the best choice. If you want to rewire a Les Paul and purchase 4 pots, its a rule of thump to use the lowest reading one for the Bridge volume, the highest reading for neck volume and the others as tone pots. Lower value pots give the bridge a more compact tone. Some people use even 300k pots there.

 

[Vasshu the humanoid typhoon]

Re: cts pots are all over the place

CTS comes in different grades...
Mostly it is more of a habit thing these days...

I have always changed CTS pots to Japanese ones, but today it is of no use either...
Everybody seems hellbent on making cheap sh!t for no good reasons!

 

[AlexR]

Re: cts pots are all over the place

Like a lot of mass produced parts in the world, the pots are made to a physical spec, not a qualitative one. The nature of the material used is that you can get small % of variation.
Pickups too have a range of K readings as a tolerance in the same range as pots, as they are wound to turn count not K. Its just one of those things that you need to understand about the making of certain parts.

Of course the beauty of pots is you can mix and match the values to suit certain positions and functions.

 

[Joey Voltage]

Re: cts pots are all over the place

+1 to what Alex said. Most off the shelf stuff you will see for guitar purposes typically will have a wider tolerance carbon composition resistive element. The tolerance specification on some as high as 20%. Carbon Comp is also very sensitive to heat, and time, and can permanently drift in value with the heat applied during soldering, as well as with age, and can fluctuate if used in an environment where a lot of heat is generated or if the resistor itself has to dissipate it (which is unlikely in a guitar). 480k - 516k is actually pretty good. You can get pots offered in tighter tolerances that use other resistive materials, but the benefits to cost are so low that it's pretty much a dead issue.

 

[beaubrummels]

Re: cts pots are all over the place

CTS can be bought in 5%, 10% or 20% tolerance. It's not a quality issue, it's what spec did you choose to buy.

In a guitar it does make a difference. I would use the higher values on the neck and lower values on the bridge to even things out.

 

[hamerfan]

Re: cts pots are all over the place

Are you shure this a quality aspect? In my book there a guy sitting there and testing parts with a multimeter. Close to 500k they go to 5% box, further away they go to 10% box ... you got the system?

 

[jeremy]

Re: cts pots are all over the place

CTS can be bought in 5%, 10% or 20% tolerance. It's not a quality issue, it's what spec did you choose to buy.

In a guitar it does make a difference. I would use the higher values on the neck and lower values on the bridge to even things out.

thats what i do as well. you can fine tune things since a 516k pot will sound a little brighter than a 480k pot

 

[beaubrummels]

Re: cts pots are all over the place

Are you shure this a quality aspect? In my book there a guy sitting there and testing parts with a multimeter. Close to 500k they go to 5% box, further away they go to 10% box ... you got the system?

The part number changes whether it's 5%, 10% or 20%. If you learn to read the stock number, you can tell what tolerance the part is before you buy it. Tighter tolerance tends to be more expensive. You just have to figure out if you want to buy a handful and test yourself, or pay for a known tighter range; whichever is worth it for you.

 

[hamerfan]

Re: cts pots are all over the place

The part number changes whether it's 5%, 10% or 20%. If you learn to read the stock number, you can tell what tolerance the part is before you buy it. Tighter tolerance tends to be more expensive. You just have to figure out if you want to buy a handful and test yourself, or pay for a known tighter range; whichever is worth it for you.

I don't give up my theory: They are testing the resistive element before they add the housing with the part number. Just a little twist to make more money an pay the resistance checking guy.

 

[AlexR]

Re: cts pots are all over the place

I think they just have a different composition of resistive material that is tighter tolerance. If your theory was accurate you would never find a 20% tolerance pot that was less than 10% out from its nominated spec, or a 10% one that was less than 5% out. And that is not the case as I have had plenty of the standard 10% pots that have been right on 500k or a few ohms out.

I can't imagine in this day and age a large firm employing someone in that sort of manner. They would have been streamlined out of there long ago.

 

[hamerfan]

Re: cts pots are all over the place

Don't blame the poor guy at the meter for his rare failures. All day long in front of a flickering display would hurt your eyes too. :crazy:

Kidding aside: CTS surely uses better components in their expensive stuff, but i still buy the cheaper ones because i never fiddle with pots. Just the bridge humucker to 9 on the volume and 8 on the tone, while neck always full on.

 

[AlexR]

Re: cts pots are all over the place

I've quite frequently got the base level cts, as long as the taper is ok and the values are about right. Most of my guitars are 2v, 2t.....so I am almost always able to deal with variance - in fact I prefer having some differences so the neck and bridge circuits get a bit of tweaking to assist them being less extreme. But so far I've yet to find any more than 20k out.

 

[GuitarDoc]

Re: cts pots are all over the place

It's common to get 10% tolerance pots. This would give a value range of 450k - 550k for pots sold as 500k pots. Even a 5% tolerance would give a range of 475k - 525k, so yours are well within the range of the best.

 

[beaubrummels]

Re: cts pots are all over the place

Just to clarify my experience on how CTS works - I bought a custom run of long shaft concentrics and pan pots, which generated custom drawings with unique part numbers.

They built a prototype and sent for review. Once a prototype was approved, the drawing was signed and the run began.

Components and parts are only rejected if bad, not repurposed if they come out different than tolerance. A normal CTS run of parts is on the order of 10,000 to 100,000 parts for military and other use. They are not going to sort individual wafers,like one guy throwing them into bin. A fair amount of testing is automated. They recycle materials of failed components but they cannot risk reusing a failed part and selling as a different 'good' part.

Guitar usage is a relatively inconsequential part of their business, though they will always build any size run if you pay the minimum amount so it's worth it to them.